1. Field of the Invention
The present invention relates to the art of electrical connectors, more particularly to an improved electrical connector assembly for connecting one or more electrical cards to a printed circuit board (PCB).
2. Description of the Related Art
With the tendency of reducing the size of a computer device, demand has arisen for increasing its data storage capacity at low cost. Generally, electrical cards, such as memory cards, are data storage devices which are electrically connected to the computer device. The electrical cards are portable instruments that are readily inserted and extracted from electrical connectors of the computer device. The connectors typically have sockets to receive the electrical cards therein and headers connected to the computer device such that data can be transferred therebetween.
Due to the ever-increasing demand in today""s Notebook Personal Computer (Notebook-PC) for high-capacity signal transmission, more electrical card connectors are arranged in xe2x80x9cdual portxe2x80x9d or stacked configurations. Examples of this electrical connector assembly are disclosed in U.S. Pat. Nos. 5,364,204 and 5,798,130. Such electrical connector assembly commonly includes an upper connector and a lower connector stacked together for receiving individual electrical cards therein and respectively electrically connecting the electrical cards to a PCB. This electrical connector assembly meets the requirement of high-capacity data transmission since it can simultaneously receive two same or different types of electrical cards therein. However, the overall size of the electrical connector assembly is not reduced at all since the electrical connector assembly simply stacks two individual electrical connectors together. It is not suitable to install such electrical connector assembly in a Notebook-PC for it occupies too much space. Furthermore, data transmission of the electrical connector assembly is achieved through independent signal contacts in an upper header of the upper connector and a lower header of the lower connector, and the signal contacts have to be directly soldered to the PCB or be connected to the PCB through a separate transition device soldered on the PCB. One problem associated with soldering the entire signal contacts of the connector assembly to the PCB is that it is difficult to solder each individual tail and ensure that none of the closely spaced solder pads is short circuited to an adjacent solder pad. In addition, if the connector assembly need be replaced or removed from the PCB, the unsoldering process can be extremely labor intensive and costly.
Therefore, the present invention is directed to solving the above problems by providing a low-profile stacked electrical connector assembly which can be used for receiving two electrical cards therein.
Accordingly, an object of the present invention is to provide a stacked electrical connector assembly having reduced height thereby saving the occupied space on a PCB where the connector assembly is mounted
Another object of the present invention is to provide a stacked electrical connector assembly with improved transition device which simplifies the assembling process of the connector assembly. The other two copending applications with unknown serial numbers, the same applicant, the same title, the same assignee and the same filing date, also disclose some other approaches to cure the shortcomings of the prior arts.
To achieve the above objects, a stacked electrical card connector assembly in accordance with the present invention comprises an upper connector, a lower connector, and a transition device respectively connected with the upper and lower connectors. The lower connector has a lower header and a lower metallic frame assembled to the lower header, and the lower frame has an opening defined therein with a plurality of spring arms extending oppositely in the opening. The upper connector has an upper header with a metallic shield covered on the upper header and a plurality of signal contacts defined in the upper header, and wherein the shield has a plurality of grounding pins extending out from one edge thereof. The transition device has a first contacting portion and a second contacting portion. The first contacting portion is contacted with the spring arms of the lower connector and the second contacting portion is connected with the signal contacts and grounding pins of the upper connector.
With such a design, data of different electrical cards received in the upper and lower connectors can be simultaneously transferred through one transition device thereby decreasing the whole height of the connector assembly. The transition device can be connected to a PCB without soldering the transition device to the PCB such that the assembling progress is simplified.
Other objects, advantages and novelty features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. Two other copending applications with unknown Serial numbers but with the same title, same applicant, same assignee and same filing date, also disclose some other approaches to overcome the shortcomings of the prior arts.